Question: When did the country Cluj-Napoca become the Principality of Transylvania?
Paraphrase: When did Cluj-Napoca change to the Principality of Transylvania?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q100188 p:P17 ?s . ?s ps:P17 wd:Q655621 . ?s pq:P580 ?value}